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That looks like a "spin off" of the old Harvey zinc gas checks applied during casting except they swage them on which takes a lot of expensive equipment. I tried the Harvey's back when they were the rage and they worked pretty well but I was shooting in a .45 ACP and that didn't justify the expense and effort so I moved on.
I'd say yes a definate spin off. Here is a couple paragraphs cut from the first Corbin link:
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The conical shape of the BG disk is what makes it work so well. The idea of using a zinc washer was tried and used with limited success in the 1950's (see the Harvey Prot-X-Bore for more info). It turned out that the washers could not be cut precisely enough to seal the bore, and that one edge was always rounded while the other was sharp. If the bullet maker put the rounded edge toward the bullet, there was no scraping or burnishing action to clear the bore. Also, if the washer was even a few ten thousandths smaller than the bullet, gas would leak around it and melt the lead into the bore.
But making the BG disk undersized and conical solved the problems. First, the disk gets its final diameter by being flattened when it is attached to the bullet. This makes the disk grow in diameter until it contacts the die walls. Then the surplus metal is forced to extrude forward and form a burnishing tool edge, because it is supported on the other side by a solid steel punch and cannot move that direction. The only way it can move it toward the relatively soft bullet material. This is exactly what we want: a base that is exactly the diameter of the bullet, with a scraper edge facing forward to clean the bore when fired.
The pity is I can "just" afford my current efforts and swaging for me is an unlikely endeavor, but I sure do like tinkering.